The new drug is the first of a new class of epilepsymedications and joins the ranks of other medications available to the estimated 2 million Americans with epilepsy. More than one-third of people with epilepsy experience seizures despite taking currently available treatments, according to the CDC.

“Some people with epilepsy do not achieve satisfactory seizure control from treatments they are currently using,” says Russell Katz, MD, director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research. “It is important to have a variety of treatment options available for patients with epilepsy.”

Epilepsy is the fourth most common neurological disorder following migraine, stroke, and Alzheimer’s disease, according to the Epilepsy Foundation. The chronic condition causes seizures brought on by abnormal electrical activity in the brain. Seizures can affect movement, the senses, emotions, and behavior.

Partial seizures, the type that Fycompa is designed to treat, are the most common type of seizure. About 60% of epilepsy patients have partial seizures, which involve only one part of the brain. They can, however, spread throughout the brain, becoming what’s referred to as generalized seizures.

In three clinical trials, Fycompa significantly reduced the frequency of partial seizures compared to placebo. But the drug does come with a host of potential side effects, including a boxed warning about serious, possibly life-threatening neuropsychiatric side effects. These include:

A few patients exhibited violent thoughts and threatening behavior. Patients should be monitored for such side effects during the early course of treatment, as their bodies adjust to the new medication.

The drug, manufactured by New Jersey-based Eisai Inc., is a once-a-day tablet to be taken at bedtime in doses ranging from 2 mg to 12 mg. According to an Eisai news release announcing its approval, the FDA has recommended that Fycompa be classified as a scheduled drug. That means it has the potential for abuse or addiction and that its distribution will be tightly controlled.